As I promised, I waited awhile then gave this game another shot. So here's more impressions.
The UI is still ridiculous, but I think I've gone off on that enough already. I've gotten used to it somewhat but it still does crazy things like sometimes you have Person A selected but all your commands affect person B. I still despise the absolute lack of being able to change your party's formation and the inverted mouse buttons too.
Being able to have 6 party members is pretty sweet. However, I don't understand why they're following me sometimes. You don't have any option to speak to them after they join you so it can get a bit odd. A somewhat non-spoilery example would be the boss lady you take along with you at the start of the game. She's one of the highest ranked Rangers and is tagging along with you to find the killer of her love. However, once you've done that she still follows you. I can see why she might do this, but she never says anything about it. She does have stuff to say about various situations so it's not like she's a mute doll, just it's a bit curious why you can't speak to your own companions. However, protip, save up your skill points on your main party members until you absolutely have to spend them. There's no reason to invest points into computer science when you get someone who basically has it maxed.
I really like the Fallouty open nature of the map while being constrained by the water system and radiation. There's lots to explore and you have to balance out the risks. I accidentally ran into a bunch of super killer death robots that could jump across the map and slice my team members in half. It was very entertaining because at that point I was still having trouble killing honey badgers. I like that kind of thing, since it makes sense that the world doesn't cater exclusively to your whims.
The customization still kinda irks me. All the weapons have their own custom models and if you equip two weapons, the other one will be slung across the back or put at the side and you can actually see them. However, all the armour doesn't show up. Whyyyyyy? I also managed to recruit a young "samurai" character but his in-game model is an old man. It's so immersion-breaking.
There are so many easter eggs in this game it's kinda crazy. It's like they had some guy who's sole purpose was to put in easter eggs.
Rocket launchers are awesome. Except against killer death robots. Then it'll just annoy them.
There's a lot of radio banter that isn't related to you once you get past the super long tutorial, which I think is great. It shows that the world can function perfectly fine without you. You can listen to other ranger squads doing their thing, raiders, all that kind of stuff. I like it. The whole radio system is great, especially since they're fully voiced.
I noticed a number of bugs still persisting, especially related to quests. Mostly things like uncompletable quests or missing items / events. It's a bit "Elder Scrolls at launch".
I really love how other rangers acknowledge what I've been doing in the wastes. It makes me feel like my actions have been noticed. Also, wear a choker when you meet your boss. It's amusing.
The main plotline isn't particularly spectacular. I already know what's going to happen, as probably will everyone playing this. There's quite a number of side things to do though, so it's not too bad. Not every game needs a vast and complex main story.
That's honestly about it.
tl;dr: It's pretty nice past the horrendous UI and a few bugs. Customization sucks.